Ellipse compass



ec. l 1951 E. W. MENNIE ELLIPSE COMPASS Filed April 8. 1946 3 Sheets-Sheet l INVENTOR.

Die@ u 195 E. W.,MENN| 2,577,905

ELLIPSE coMPAss Filed April e. 194e s sheets-sheet 2 HTrdF/YEKS,

Dec. H, 1951 E, w MENME 2,577,905

ELLIPSE COMPASS Filed April 8. 1946 3 Sheets-Sheet 3 Patented Dec. 11, 1951 ELLIPSE COMPASS Edward William Mennie, Windsor, ntario,. Canada, assignor to Howard H. Crawford, Detroit,

Mich.

Application April 8, 1946, Serial No. 660,489

9 Claims.

This invention relates generally to scribing mechanism and more speciiically toward an ellipsograph adapted to trace the closed intersection of a cylinder with a plane surface.

An object of this invention is to provide a novel mechanism by which the closed intersection of a cylinder with a surface may quickly, accurately, and easily be traced on the surface.

Another object is to provide such a mechanism which may be adjusted to trace the closed intersection of a cylinder with a surface intersecting the same at any desired angle.

Another object of this invention is to provide such a means by which the closed intersection of a cylinder with a plane surface may be described or traced for any desired diameter cylinder.

Another object is to provide such a mechanism which is simply and easily operated.

Other objects will be apparent from the drawings, the speciiication, and the appended claims.

In the drawings to be taken as a part of this specification there is shown a preferred embodiment of the invention, in which like reference numerals are used to designate like parts in the various figures.

Fig. l is a View in front elevation showing an ellipsograph embodying the invention;

Fig. 2 is a plan view of the ellipsograph shown in Fig. 1;

Fig. 3 is a side elevational View of the ellipsograph shown in Figs. 1 and 2;

Fig. 4 is a view similar to that of Fig. 1, but showing the ellipsograph adjusted to draw a different closed intersection; and

Fig. 5 is a plan view of the ellpsograph adjusted as shown in Fig. 4.

The ellipsograph l comprises a base or supporting member 2, an arm member 4 fulcrumed on a pivot screw 6, linkage 8 carrying a scriber-holding member IIJ, a reciprocal and rotatable rod I4 carrying an arm or link member I5 which is connected to the upper end portion of the scriber member IU by a universal joint mechanism I6. A marking element I1 carried by member II is adapted to trace an ellipse I8 or closed intersection with the surface I9, upon which the ellipsograph I is positioned, with a right cylinder having its axis extending parallel to the axis of rotation of the member I4. The supporting member 2 comprises a substantially quadrant-shaped platelike member 20 held perpendicularly to the surface I9 by a bracket 2| extending substantially perpendicularly outwardly from and carried by the front surface 22 of the member 20. The bottom edge 23 of the member 20 rests on the surface I9, and

j an edge 24 extends upwardly at right angles to the edge 23. The screw 6 extends through an aperture in the member 20 spaced above the edge 23 with its center substantially in a plane parallel to surface I9 extending through the center of movement of the joint mechanism I6 and is spaced slightly away from the edge 24. The edges 23 and 24 are connected by a quarter circle section 26 with the screw 6 as its center and tangentially arranged end portions adjacent the edges 23 and 24.

The arm member 4 comprises an L-shaped member 30 having its longer arm 32 journaled aboutthe pivot screw 6 and held in place by a thumb nut 34 screw-threaded on the screw 6. A second screw 36 extends through an aperture in the arm 32 adjacent the circle section or curved surface 26 and has its head 38 held in engagement with the platelike member 20 by a thumb nut 40 whereby the arm 32 may be clamped at the desired anglerelativelto the surface I9. Suitable indicia 42 on the platelike member 20 co-operate with the longer arm 32 to indicate the angular position of the arm 32 relative to the surface I9. As will be described more fully hereinafter, this is the angle which the cylinder whose intersection with the surface is to be traced by the marking point I1 makes with the surface I9.

The reciprocal and rotatable rod I4 is carried vby a shorter arm 43 of the L-shaped member 30 extending substantially perpendicularly outwardly from` the plane of the platelike member 20 and a member 44 having a right-angle flange 46 suitably secured as by welding to the arm 32. The member 44 is spaced from and extends substantially parallel to the arm 43 and co-operates with the arm 32 to provide a substantially U-shaped formation. Aligned apertures extend through the outer ends of the arm 43 and member 44 for receiving ja bushing or a bearing member 43 in which the reciprocal and rotatable rod I4 is journaled. The outer end of the rod I4 extending beyond the shorter arm 43 preferably has a head portion 52 whereby the operator may easily impart rotational and reciprocal movement thereto. The'other end ofthe rod I4 extending toward the surface I9 is preferably flattened and apertured to provide a substantially annular portion 54 having its axis perpendicularly to the longitudinal axis of the rod I4 for receiving a clevis 56. The clevis 56 has apertures extending through its ears aligned with the aperture through the flattened 'end portion 54 for receiving a thumb screw 58. Preferably the aperture through the ear of 55 the clevis member 56 closest to the platelike mem- 3 ber 28 is screw-threaded to receive the thumb screw 58 while the aperture through the other ear of the clevis 56 has a clearance t with respect to the screw threads on the thumb screw 58 whereby the thumb screw may be tightened to clamp the clevis 58 to the flattened end portion 54 at any desired angle.

One lever ll of the linkage 8l isl pivoted to.. the outer end portion of the bracket 2I away from the member 20 by a rivet 60. A second lever 1 2` of linkage 8 has one end portion pivotally secured to the end portion of the lever 'I0 opposite the rivet 80 by a guide pin 14 and its other end lpQrr tion 'I5 laterally oiset upwardlygawayironthe surface I8 to receive the scriber member I8 so that its marking point or element `I"I will beheldY continuously against the surface I8. The g'uide pin 'I4 has a downwardly extending tapered por-k` tion 18 which is adapted; to slide along surface la as the element n .is nved to trace the euipse I8 to maintain the plane of the levers, parallel to the vsurface I9. The universal joint mechanism I connects one end of the arm or link member I5 to the upper end of the scriber member I0, and the other end portion is screw-threadedly secured -to the connecting base portion of the clevis 56. If desired, indicia may beplaced on the clevis 56 and annular portion 54 whichmay be calibrated to indicate inches, radius of the intersecting cylinder, or minor axis of the ellipse.

The operation `of the ellipsograph I is as follows and'V may best be understood byreferring to Figs. 4 and 5.. Thumb nuts 34 and 40 are loosened and the L-shaped lever 30 adjusted in accordance with the indicia 42 toagree with the angle from thehori'zontal or the surface Iia't which the longitudinal axis of the cylinder whose curved or closed intersection with the surface'. I9 is to be traced bythem'arkin'gpoint I'I. Thumb nuts 34 and 4,0 are :then tightened t'o holdthe lever arm or member 30 'in its adjustedV position. Next the rod .I4 isrotated by means of the. Head' portion 52, `so that the link member. I5. extends substantially in -a planelying along the longitudinal axis of therd I4 and perpendicularlyto the plane of the platelike member 20. The thumb screw 58 is then losened yand .thelink member I5 movedout of alignment with the longitudinal axis of the rod I4 asuicient distance sothat the marking point I'I is displaced either4 towadior away from the platelike member 20 frlth' longitudinal centerline of the 'rdfI4 `a`. distance equal to the radius ofthe eylinde whose closed intersection with the surface I9V is t6 belt'raced'.' This, as will be evident from Fig. 5, is the minor axis of the ellipse I8. ,Thumb screw 58 is then tightened to securely hold the 'rod I4 and' link member I5 at a xed relative angle. Itwlll be noted from the foregoing that theangle .between the rod I4 and link member I5 is a measure Aof, the radius of the cylinder whose closed intersection is to be traced on the surface. IS Yand of the minor axis of the ellipse I8 which is desired to be traced. As stated hereinbefore, sui-table indicia may be usedon the clevis 56 .and annular portion 54 so that this radius or angle between the rod I4 and link member I5 may be set Without measuring.

The minor axis of the ellipse I8 having been determined and the angle at which theeylinder intersects the plane having been determined by the setting of the L-shaped member .30, relative to the platelike member 20 in accordance with indicia 42, the major axis of theellipse willen-to,- Inatically be determined. To tiae the ellipse I8;

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the operator grasps the head portion 52 and pushes the rod I4 downwardly through the bearing member 48, at the same time allowing the rod I4 to rotate along its longitudinal axis. This movement is continued until the marking point I1 reaches the major axis of the ellipse I8. Rotation ofthe. head .portion 52 is continued thereafter in the samedirection; however; rthe rod I4 must now be pulled outwardly through the bearing member 48 until the marking point I1 reaches the other end of the major axis. As before, rota- 'tion` f the head portion 52 in the same direc- Ytion .is continuedbut the rod I4 must be pushed inwardly` throughthe bearing member 48 until the marking point' I1 reaches the minor axis of theA ellipse'I or the starting point. It should be noted' that the' ell'ipsograph I traces an ellipse, the major axis of which lies in a vertical plane extending through the axis of the rod I4 and the minor axisof which lies' in .a vertical plane extending perpendicularly to member 20 and through the axis of pivot screw' 6. In other words, the axis of the rod I4 must be positioned in the same vertical plane as the axis of the cylinder.

y The ellipsograph I is relatively simple inv operation, because thetraced ellipse I8 isa resul-t of the intersection of two points movable in two diierent planes. It 4will be evident that the linkage means 8 holding the scriber member I0 permits movement of the scribermember I0 in the plane of thesurfacel lil.` ,Movement ofthe end portion of the link member'- I5 a'waygfrom clevis 56, upon rotation ofVA the rod I4and without longitudinalreciprocal ,movement of rod I4 will be in a plane perpendicular to the. longitudinal axis of the rod I4. `Sinc'ie the scriber member .I0 and the link member I5Vare rigidly secured together and the member I II can move only in the plane of surface I9, the rod I 4 must move longitudinany in the' bearing member 4b so that the locus of movement of the link member I 5 vwill always be in the plane if movement of the center of movement of the universal joint mechanism Y I6. Therefore the result of rotation' of the head portion 52 in an endeavor move the scriber member I 0 aboutthe surface I2 will cause the rod I4 to reciprocate in its bearing member 48;.

or, conversely, if the operator reciprocates the I rod I4 in the bearing member 48, the rod I4, due

to the action of the linkage means 8, will automatically rotate about itsl'orngitudinal axis.

It may now be that this invention provides an instrument for drawing the closed in- Y tersection of a cylinder with a plane surface which is extremely simpl-e to operate and does not require a hig'h degree of skill to move a scribing nieansitwo different planes at the same time. Byits'construction; movement of the scriber member inone direction will automatically moveY it .in a.' second direction due to the interaction` of .theelemen'ts The device is simple and contains a minimum f parts, and the adjustments forv determiningthe size of the ellipse is in tefmscf known factors which are the radius of the cylinder` which intersects vthe planar surface arid the angle f intersetio of the cylinder with the surface. y

Having thus described oneernbodiment of this invention, it is now desiredA to claim and secure the surface, means carried b'y said member and s having a portion movableparallelfto the surface, marking means carried by said portion andhav'- ing a portion adapted to engage the surface for scribing thereon, rotatable means carried by said member at the same angle relative to the surface as the angle the cylinder bears tothe surface, means carried by said rotatabl-e means and extending at a selectively xed angle therefrom proportional to the minor axis of the closed intersection for transmitting transverse movement to said first-named portion uponrotation of said rotatable means, and means securing an end portion of said last-named means to said firstnamed means for movement parallel to the surface whereby upon rotation of said -rotatable means said first-named means causes said rotatable means to move longitudinally along its axis.

y V2. An ellipsograph comprising a support, pivoted lever members pivotally carried by said support and having a portion thereof movable in a plane parallel to and spaced from the plane of the surface upon which said support is positioned, scribing means carried by said portion and having a portion adapted to mark in the plane of the surface upon which said support is positioned, an elongated member carried for reciprocating movement by said support with its longitudinal axis extending at an angle to said planes, a member rigid with said elongated member and connecting one of said portions with said elongated member whereby said one portion holds the point of connection of said elongated member with said one portion for movement in a plane parallel to said surface, and means whereby said elongated member may be reciprocated relative to said support.

3. An ellipsograph comprising a support, linkage carried by said support and having a portion movable substantially parallel 4to but spaced from the surface upon which said support may be positioned, marking means carried by said portion and adapted to scribe aline on the surface, rotatable and reciprocable means carried by said support, a connecting member carried by said lastnamed means and rotatable therewith, and means connecting said connecting member to said portion whereby said portion constrains the point of connection of said connecting member with said portion for movement in said parallel plane whereby rotation and reciprocation of said rotatable means will cause said marking means to scribe an ellipse on the surface.

4. In an ellipsograph for tracing an ellipse on a planar surface, an L-shaped supporting member adapted to be positioned on the surface, an L-shaped arm member having one leg pivotally carried by one leg of said supporting member and adapted for pivotal movement in a plane substantially perpendicular to the surface, linkage carried by the other leg of said supporting member and having a path of movement substantially parallel to the surface, scribing means carried by said linkage for marking the surface, an elongated member carried by the other leg of said arm member and having an end portion extending toward the surface, means selectively positioning said arm member about its pivot whereby the angle of said elongated member relative to the surface may be determined, a connecting member carried by and extending at a selectively fixed angle to said elongated member one end portion and having a second portion secured to said linkage whereby said scribing means is moved along the surface to mark an ellipse thereon upon rotation and reciprocation of said elongated member.

5. An ellipsograph for describing an ellipse on a planar surface comprising a platelike member,

securing said members against relative movement, a laterally extending foot member secured to one face of said platelike member, linkage means pivotally carried by said foot member and having a portion movable in a plane parallel to the planar surface. scribing means carried by said portion and adapted to mark the surface, an elongated rod member carried by the other of said arm member legs and extending substantially parallel to said arm member one leg and supported for longitudinal and rotational movement, a second rod member, means selectively securing one end portion of said second rod member to one end portion of said elongated rod member at an angle relative thereto proportional to the minor axis of the ellipse, and universal joint means securing the other end portion of said second rod member to said portion of said linkage means.v

6. An ellipsograph for describing an ellipse on a planar surface -comprising a platelike member, fulcrum means on said member, an L-shaped arm member having one of its legs fulcrumed on said means and movable in a plane parallel to that of said platelike member, means selectively securing said members against relative movement, a laterally extending foot member secured to one face of said platelike member, linkage means pivotally carried by said foot member and having a portion movable in a plane parallel to the planar surface, scribing means carried by said portion and adapted to mark the surface, an elongated rod member carried by the other of said arm member legs and extending substantially parallel to said arm member one leg and supported for longitudinal and rotational movement, indicia means carried by Said platelike member for indicating the angle between said elongated rod and the surface, a second rod member, means selectively securing one end portion of said second rod member to one end portion of said elongated rod member at an angle relative thereto proportional to the minor axis of the ellipse, and universal joint means securing the other end portion of said second rod member to said portion of said linkage means.

7. A device for marking the closed intersection of a cylinder with a surface comprising a supporting member adapted to be positioned upon the surface, means carried by said member and having a portion movable parallel to the surface, marking means carried by said portion and having a portion adapted to engage the surface for scribing thereon, a member having a portion thereof pivoted to said supporting member and adapted to be pivoted to selected positions about its pivot, rotatable means carried by said pivoted member at the same angle relative to the surface as the angle of the cylinder bears to the surface, means carried by said rotatable member and extending at a selectively fixed angle therefrom proportional to the minor axis of the closed intersection for transmitting transverse movement to said ilrst-named portion upon rotation of said rotatable means, and means operatively connecting said last-named means to said marking means including a pivot movable in a plane parallel to the surface, the pivoted connection of said pivoted member portion to said supporting member being in the same plane as the plane of movement of said last-named pivot.

8. An ellipsograph comprising a support, pivantena oted lever members pivotally carried by said snp! port and having a portion thereof Amovable in a plane parallel to and spaced from the plane of the surface upon which said support is positioned, scribing means carried by said portion and hav.- ing a portion adapted to mark in the plane ci the surface upon which said support is positioned, an elongated member carried for reciprocating movement by said support with its longitudinal axis extending at an angle to said plane, a member rigid with said elongated member and having a universal connection with one of said portions, the path of movement of said universal connection being in a plane parallel to said surface, a supporting member having a pivotal connection with said support for carrying said elongated member. said pivotal connection lying in the plane of movement of said universal connection, and means whereby said elongated member may be reciprocated relative to said support.

9. In a device for marking the closed intersection of a cylinder with a surface, a supporting member adapted to be positioned on the surface adjacent the closed intersection, reciprocative means carried by said member and having its axis of reciprocation parallel to the axis of the cylinder, positioning means carried by said member and having a portion movable in a path located above and parallel to the surface, means carried by said portion and engageable with the surface for marking the lclosed intersection, means eat-J ried'by said reciprocative means and adapted for rotation about the axis of said reciprocative means and having a portion spaced from said reciprocative means axis a distance equal to the radius of suchl cylinder, means connecting said portion of said means carried by said reciprocative means to said positioning means portion whereby said portion of said means carried by said reciprocative' means is constrained to move in said parallel path .so that reciprocation of said reciprocative means will rotate said rotatable means for movement of said marking means along the closed intersection.

EDWARD WILLIAM MENNIE.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 677,590 Oldeld July 2, 1901 988,188 Graham Mar. 28, 1911 FOREIGN PATENTS Number Country Date 150,641 Germany Apr. 23, 1904 141,400 Great Britain Apr. 12, 1920 99,399 Austria Mar. 10, 1925 

